1. Field of the Invention
The present invention relates to a knit fabric made with non-elastic yarn and a minor weight fraction of elastic combination yarns. More particularly, the invention concerns such a knit fabric in which the combination yarn has an elastic elongation of 10% to 70% and provides improved fabrication, shape-retention and appearance to fabric knit therewith.
2. Description of the Prior Art
Knit fabrics which contain non-elastic textile yarns and a minor fraction of elastic combination yarns are known. Such fabrics are used for sweaters, socks and the like. For example, Strauss et al, U.S. Pat. No. 5,050,406, discloses a knit fabric that comprises 30% core-spun combination yarn, in which the yarn is 90% cotton and 10% spandex. Also, Muller et al, U.S. Pat. No. 3,392,552, describes a knit fabric, in which at least 20% of the ends are of elastic yarn plied with inelastic yarn.
Various types of elastic combination yarns are known, such as covered, core-spun, plied, core-effect, plaited, air-jet-entangled and like yarns. In such yarns, elastic filaments are combined with non-elastic textile yarns by known techniques. In the manufacture of some combination yarns, the elastomeric components are stretched during combination with inelastic yarn. For example, Strachan, U.S. Pat. No. 3,940,917, discloses a spandex yarn being stretched at least 100%, usually 250 to 500%, during air-jet entanglement with inelastic filaments, and Miyasaka, Japanese Patent Application 38-50045, discloses an elastic yarn being stretched 50% during a similar entanglement procedure.
Although non-elastic textile yarns and elastic combination yarns have been used together in various knit fabrics, the utility of such fabrics in manufactured garments such as sweaters, socks, and the like, has been somewhat limited. Incorporation of elastic combination yarns into such fabrics often resulted in undesirable "working loss" (i.e., area contraction) in the fabrics immediately after the fabric was removed from the knitting machine on which the fabric was made. However, various garments knit from natural fibers, such as cotton and wool, without any elastic yarns in the fabric, often suffer problems of shape distortion during finishing, cleaning and storage.
An object of this invention is to provide an improved knit fabric in which the problems of working loss and shape distortion are significantly decreased.